change ABIArgInfo to hold its llvm type with PATypeHolder so that it doesn't dangle as types get refined.  This fixes Shootout-C++/lists1 and probably also PR7522.
change ABIArgInfo to hold its llvm type with PATypeHolder so that
it doesn't dangle as types get refined.  This fixes Shootout-C++/lists1
and probably also PR7522.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@107196 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang